In this era where cryptocurrency assets frequently face hacking attacks, have you ever wondered: Is there a wallet that can truly achieve 100% security, never connect to the internet, and be completely under your control?
The answer is: Yes, and you can build it yourself.
No need to purchase any hardware wallets, no complex code is required; just one old computer can build your air-gapped cold wallet system 👇
🧱 One, Why Build Your Own Cold Wallet?
Common wallets on the market (including Ledger, Trezor) are relatively secure, but still rely on firmware, servers, or even USB ports—there is theoretically still a possibility of being compromised.
Advantages of building your own cold wallet:
Completely offline, not connected to the internet
Not relying on third-party companies
Highest security level
The cost is almost zero (just need an old computer)
🛠️ Two, Prepare Materials
The devices you need are extremely simple:
🖥️ An old computer (or Raspberry Pi)
💾 A USB or SD card (for transferring transaction data)
🔐 A secure storage place (fireproof safe, metal plate, paper backup)
🧑💻 A clean operating system (recommended: Ubuntu, Tails, or Windows)
📌 Remember: This device will never connect to the internet; Wi-Fi and Ethernet must be turned off.
🧩 Three, Setup Methods
✅ Method 1: Use an old computer to install a new system.
Restore factory settings to clear all old data
Install operating systems like Ubuntu or Windows.
Disable network functions in the BIOS
Completely isolated network environment, never connect to the internet
✅ Method 2: Use a bootable Live OS
Download Tails or Ubuntu system
Write to USB using balenaEtcher.
Boot from USB every time, no hard drive needed, leaving no trace.
🔐 Four, Install Cold Wallet Software (offline installation recommended)
Bitcoin-specific wallet:
Electrum: Lightweight, supports offline signing
Sparrow Wallet: Strong privacy, feature-rich.
Specter Desktop: Supports multi-signature configuration
Multi-currency support:
Unstoppable Wallet: BTC / ETH / Multi-chain
MyEtherWallet: Ethereum and ERC-20.
Wasabi Wallet: Strong privacy, Bitcoin-specific
🔍 Always verify the PGP signature before installation to confirm the security of the software download source.
📄 Five, Steps to Create a Cold Wallet
Open the wallet program and select 'Create New Wallet'
Generate a mnemonic phrase (12 or 24 words) — write it down by hand, do not screenshot or store it in the cloud.
Set a strong password (optional but recommended)
Generate a receiving address and prepare to receive coins.
💸 Six, How to Use Cold Wallets to Send and Receive Coins?
Receiving coins:
Open the offline wallet and generate a receiving address
Send coins to this address from an online device
It is recommended to use a watch-only wallet to track balances
Sending coins:
Create unsigned transactions (.txn file) on an online device
Transfer to the cold wallet using USB or QR code
Sign on the cold wallet, then export the signed transaction
Return to the online device to broadcast the transaction on-chain and complete the sending.
The benefit of doing this is: the private key never leaves the offline device, and hackers can never steal it.
⚠️ Seven, Key Reminders
If you are not familiar with computers, the internet, or operating systems, be sure to learn the basics in advance.
A small mistake can lead to assets being unrecoverable.
Be sure to back up your mnemonic phrase; never save it on connected devices or cloud services.
✅ Conclusion:
"True security is not relying on others, but being in control yourself."
Creating an offline cold wallet may sound complex, but it is actually very practical and feasible.
What you need is not technical talent, but attention to detail, patience, and a bit of hands-on ability.
Once set up, you will have a wallet system that is more secure and unbreakable than any hardware wallet on the market.
🧱 Security starts with you, wealth is under your control.
Are you ready to build your own cold wallet fortress?
